Example #1
0
func handleDegraded() {

	// If we become degraded, drop all clients.
	if store.Degraded() {
		connectionsLock.Lock()

		for conn, _ := range connections {
			conn.conn.Close()
		}
		connections = make(map[*userConn]bool)

		sessionsLock.Lock()
		sessions = make(map[uint64]*userConn)
		sessionsLock.Unlock()

		waitingLock.Lock()
		waiting = make(map[uint64]*userConn)
		waitingLock.Unlock()

		connectionsLock.Unlock()

	} else {
		sessionsLock.Lock()
		defer sessionsLock.Unlock()

		// If we've become undegraded...
		// Check for attached sessions without connections.
		checkOrphanAttaches()

		// Check for nameless users.
		checkNameless()
	}
}
Example #2
0
func Forward(node uint16, userMsg *UserMessage) {
	store.StartTransaction()
	defer store.EndTransaction()

	// While degraded, we drop all messages.
	if store.Degraded() {
		return
	}

	// If we have no connection to that node, we drop the message.
	if len(connections[node]) == 0 {
		return
	}

	// Otherwise, send to the given node.
	var forward rproto.Forward
	forward.Sender = new(uint64)
	forward.Recipient = new(uint64)
	forward.Tag = new(string)
	forward.Content = new(string)
	forward.Ttl = new(uint32)
	*forward.Sender = userMsg.Sender
	*forward.Recipient = userMsg.Recipient
	*forward.Tag = userMsg.Tag
	*forward.Content = userMsg.Content
	*forward.Ttl = uint32(userMsg.Ttl)

	connections[node][0].SendProto(2, &forward)
}
Example #3
0
func handleDegraded() {

	// If the node becomes degraded, drop all relay connections.
	if store.Degraded() {
		for _, nodeConns := range connections {
			for _, conn := range nodeConns {
				conn.Close()
			}
		}
		connections = make(map[uint16][]*connect.BaseConn)
	}
}
Example #4
0
func Startup() {
	store.StartTransaction()
	defer store.EndTransaction()
	sessionsLock.Lock()
	defer sessionsLock.Unlock()

	// If undegraded, check for attached users with no session,
	// or nameless users in the store.
	if !store.Degraded() {
		checkOrphanAttaches()
		checkNameless()
	}

	// Start accepting client protocol connections.
	go connect.Listen(connect.CLIENT_PROTOCOL, incomingConn)
}
Example #5
0
func handleDegraded() {

	// If we become degraded, close all follow connections
	// aside those receiving bursts.
	if store.Degraded() {

		connectionsLock.Lock()

		for _, conn := range connections {

			conn.lock.Lock()

			if !conn.receivingBurst {
				conn.Close()
			}

			conn.lock.Unlock()
		}

		connectionsLock.Unlock()
	}
}
Example #6
0
func incomingConn(node uint16, conn *connect.BaseConn) {

	store.StartTransaction()
	if store.Degraded() {
		conn.Close()
		store.EndTransaction()
		return
	}

	userConn := new(userConn)
	userConn.conn = conn
	userConn.deliver = make(chan *relay.UserMessage, 100)

	// Add to connections set.
	connectionsLock.Lock()
	connections[userConn] = true
	connectionsLock.Unlock()

	store.EndTransaction()

	go handleConn(userConn)
}
Example #7
0
func process() {

	for {
		select {

		// Try to make any needed outgoing connections.
		case <-tryOutgoingCh:
			store.StartTransaction()
			connectionsLock.Lock()

			coreNodes := config.CoreNodes()
			if !store.Degraded() {
				if config.IsCore() {
					for _, node := range coreNodes {
						if node == config.Id() {
							continue
						}

						if connections[node] == nil {
							go tryOutgoing(node)
						}
					}
				} else {

					// Settle for less than 2 core nodes,
					// if there *aren't* 2 core nodes.
					targetConns := 2
					if targetConns > len(coreNodes) {
						targetConns = len(coreNodes)
					}

					newOutgoing := targetConns -
						len(connections)

					used := -1
					for newOutgoing > 0 {
						r := processRand.Intn(
							len(coreNodes))

						// Don't do the same node
						// twice.
						if r == used {
							continue
						}

						node := coreNodes[r]
						if connections[node] == nil {
							used = r
							go tryOutgoing(node)
							newOutgoing--
						}
					}
				}
			} else {
				if len(connections) == 0 {
					r := processRand.Intn(len(coreNodes))
					node := coreNodes[r]
					if connections[node] == nil {
						go tryOutgoing(node)
					}
				}
			}

			connectionsLock.Unlock()
			store.EndTransaction()

			// After a random time, check again.
			randDur := time.Duration(processRand.Intn(19)+1) * time.Second
			tryOutgoingCh = time.NewTimer(randDur).C

		// New received connection.
		case conn := <-receivedConnCh:

			conn.offerTimers = make(map[uint64]*time.Timer)

			store.StartTransaction()
			connectionsLock.Lock()

			// If we are degraded, reject the connection,
			// unless we have no other connection,
			// and it is outbound.
			if store.Degraded() &&
				!(len(connections) == 0 && conn.outgoing) {

				conn.lock.Lock()
				conn.Close()
				conn.lock.Unlock()
				connectionsLock.Unlock()
				store.EndTransaction()
				break
			}

			// If we have an existing connection to this node,
			// close it.
			if connections[conn.node] != nil {
				other := connections[conn.node]

				other.lock.Lock()

				other.Close()
				if other.firstUnappliedTimer != nil {
					other.firstUnappliedTimer.Stop()
				}

				other.lock.Unlock()
			}

			// Add to our connections.
			connections[conn.node] = conn

			// Send initial position and leader messages.
			posMsg := new(fproto.Position)
			posMsg.FirstUnapplied = new(uint64)
			posMsg.Degraded = new(bool)
			*posMsg.FirstUnapplied =
				store.InstructionFirstUnapplied()
			*posMsg.Degraded = store.Degraded()
			conn.conn.SendProto(2, posMsg)

			proposal, leader := store.Proposal()
			leaderMsg := new(fproto.Leader)
			leaderMsg.Proposal = new(uint64)
			leaderMsg.Leader = new(uint32)
			*leaderMsg.Proposal = proposal
			*leaderMsg.Leader = uint32(leader)
			conn.conn.SendProto(11, leaderMsg)

			connectionsLock.Unlock()
			store.EndTransaction()

			// Start timer for sending first unapplied
			// instruction updates.
			if config.IsCore() && conn.node <= 0x2000 {
				conn.lock.Lock()

				conn.firstUnappliedTimer = time.AfterFunc(
					firstUnappliedTimerDuration,
					func() { conn.firstUnappliedTimeout() })

				conn.lock.Unlock()
			}

			// Start handling received messages from the connection.
			go handleConn(conn)

		// Terminated connection.
		case conn := <-terminatedConnCh:

			connectionsLock.Lock()

			if connections[conn.node] == conn {
				delete(connections, conn.node)

				conn.lock.Lock()

				conn.closed = true
				if conn.firstUnappliedTimer != nil {
					conn.firstUnappliedTimer.Stop()
				}

				conn.lock.Unlock()
			}

			connectionsLock.Unlock()
		}
	}
}
Example #8
0
func handlePosition(f *followConn, content []byte) {
	store.StartTransaction()
	defer store.EndTransaction()
	f.lock.Lock()
	defer f.lock.Unlock()

	if f.closed {
		return
	}

	var msg fproto.Position
	if err := proto.Unmarshal(content, &msg); err != nil {
		f.Close()
		return
	}

	if config.IsCore() && f.node <= 0x2000 {
		store.SetNodeFirstUnapplied(f.node, *msg.FirstUnapplied)
	}

	if store.Degraded() && *msg.Degraded {
		f.Close()
		return
	}

	start := store.InstructionStart()
	if *msg.FirstUnapplied < start {

		f.sendingBurst = true
		burstMsg := new(baseproto.Message)
		burstMsg.MsgType = new(uint32)
		burstMsg.Content = []byte{}
		*burstMsg.MsgType = 3
		f.conn.Send(burstMsg)

		go sendBurst(f)

		return

	} else if *msg.FirstUnapplied <= store.InstructionFirstUnapplied() &&
		*msg.Degraded {

		f.sendingBurst = true
		burstMsg := new(baseproto.Message)
		burstMsg.MsgType = new(uint32)
		*burstMsg.MsgType = 3
		f.conn.Send(burstMsg)

		go sendBurst(f)

		return

	} else if *msg.Degraded {
		f.Close()
		return
	}

	// Send all chosen instructions above the first unapplied point.
	instructions := store.InstructionSlots()
	relativeSlot := int(*msg.FirstUnapplied - store.InstructionStart())
	for ; relativeSlot < len(instructions); relativeSlot++ {
		slot := store.InstructionStart() + uint64(relativeSlot)
		slotValues := instructions[relativeSlot]
		if len(slotValues) != 1 || !slotValues[0].IsChosen() {
			continue
		}

		// Convert the change request to our internal format.
		sendInstructionData(f, slot, slotValues[0].ChangeRequest())
	}
}
Example #9
0
func process() {

	// Try to make an outgoing connection to all other client nodes,
	// if we're not in a degraded state.
	store.StartTransaction()
	if !store.Degraded() {

		for _, node := range config.ClientNodes() {
			if node == config.Id() {
				continue
			}

			conn, err := connect.Dial(connect.RELAY_PROTOCOL, node)
			if err != nil {
				// No luck connecting.
				continue
			}

			connections[node] = append(connections[node], conn)
			go handleConn(node, conn)
		}
	}
	store.EndTransaction()

	// Retry connections once per config.CHANGE_TIMEOUT_PERIOD
	// Largely arbitrary.
	reconnectTicker := time.Tick(config.CHANGE_TIMEOUT_PERIOD)

	for {
		select {

		// Connection retry tick.
		// If not degraded, try to make an outgoing connection to any
		// client node that we do not have at least one connection to.
		case <-reconnectTicker:

			store.StartTransaction()

			// Do not attempt to make connections while degraded.
			if store.Degraded() {
				store.EndTransaction()
				break
			}

			for _, node := range config.ClientNodes() {
				if node == config.Id() {
					continue
				}
				if len(connections[node]) > 0 {
					continue
				}

				conn, err := connect.Dial(
					connect.RELAY_PROTOCOL, node)

				if err != nil {
					// No luck connecting.
					continue
				}

				connections[node] =
					append(connections[node], conn)
				go handleConn(node, conn)
			}

			store.EndTransaction()

		// New received connection.
		case receivedConn := <-receivedConnCh:
			node := receivedConn.node
			conn := receivedConn.conn

			store.StartTransaction()

			// If we are degraded, reject the connection.
			if store.Degraded() {
				conn.Close()
				store.EndTransaction()
				break
			}

			// Add to our connections.
			connections[node] = append(connections[node], conn)

			store.EndTransaction()

		// Terminated connection.
		case receivedConn := <-terminatedConnCh:
			node := receivedConn.node
			conn := receivedConn.conn

			store.StartTransaction()

			// Remove this connection from our connection list.
			index := -1
			for i, _ := range connections[node] {
				if conn == connections[node][i] {
					index = i
					break
				}
			}
			if index != -1 {
				connections[node] =
					append(connections[node][:index],
						connections[node][index+1:]...)
			}

			store.EndTransaction()
		}
	}
}